1. Field of the Invention
This invention relates to semiconductor chip packages, more particular to a carrier for one or more chips, which exhibits excellent thermal properties in dissipating heat from a carried chip and a method of manufacture of such carrier.
2. Description of the Prior Art
Various chip carriers have been proposed and constructed which include a ceramic substrate and a die-cavity into which the chip or die is placed. The die or chip is typically a semiconductor device or large scale integrated circuit. The chip is interconnected to a metallization pattern on the ceramic, non-conductive substrate surface and a grid array of pins electrically connected to the pattern, the pins in turn, being adapted to plug into another integrated circuit chip carrier socket or to a printed circuit mother board. It has been recognized that the heat generated by an operating chip may be detrimental not only to the chip itself but to other adjacent electronic components and overall package integrity. Heat has been removed heretofore by heat conduction passage through the pins and the ceramic material. This is not an efficient way of removing heat and entails integrated circuit and packaging design considerations which limit the number of the pins in a particular array and the efficiency and overall capability of the integrated circuits. As chips and chip packages become more and more miniaturized the problem of heat generation and the need for heat dissipation becomes more acute.
U.S. Pat. No. 4,338,621 recites various prior art heat dissipating means including IBM Technical Disclosure Bulletin Vo. 22, No. 4, Sept. 1979, page 1428-29 which shows a carrier including a primary upper heat sink through which coolant fluid is passed and a lower heat sink surrounding the die cavity and attached by solder to a metallized ceramic substrate on which chips are preplaced, the resultant carrier being then affixed by solder to a circuit board. The '621 patent provides a base member and cover member having mating electrical pads and in which both members are formed of thermally conductive ceramic material to dissipate heat from a chip bonded to an interior surface of the base member. The carrier faces an open-air stream with optional cooling fins being provided to enhance heat dissipation. The chip carrier hereafter described obviates the more complicated heat rejection techniques heretofore known in the chip carrier art and results in improved heat dissipation for the higher power integrated circuits.